There have been two sets of dragons that I know of (maybe 3 if the Jills are separate from the Cyrodiilian)

There are the people on the other continent - and are there still Tiger Dragons? Others will be able to add more but didn't they become extinct or something?

then there are the carcasses of the Dragons in the Battlespire - Mehrunes Dagon murdered them while they were dormant when he invaded the Spire

if dragons are anything like god-level then they would sleep in the dreamsleeve and not get memory-wiped. would they be after Dagon's blood? just a bit?